addSubQueryJoin example

    // So instead we trick the filter into using the alias of the base table.     // See https://www.drupal.org/node/271833.     // If a relationship is set, we must use the alias it provides.     if (!empty($this->relationship)) {
      $this->tableAlias = $this->relationship;
    }
    // If no relationship, then use the alias of the base table.     else {
      $this->tableAlias = $this->query->ensureTable($this->view->storage->get('base_table'));
    }

    $this->addSubQueryJoin($this->value);
  }

}

if (!empty($this->options['break_phrase'])) {
      $break = static::breakString($this->argument);
      if ($break->value === [-1]) {
        return FALSE;
      }
      $tids = $break->value;
    }
    else {
      $tids = $this->argument;
    }

    $this->addSubQueryJoin($tids);
  }

  public function title() {
    $term = $this->termStorage->load($this->argument);
    if (!empty($term)) {
      return $term->getName();
    }
    // TODO review text     return $this->t('No name');
  }

}